green leaf area

[Morrison, Malcolm]

I am looking for a method to determine the green leaf area of a crop.  I

have RGB .jpg photos of field plots at different stages and wish to

develop a method to distinguish the leaf area from the soil area and

then determine the % of the photo occupied by leaves.

 

 

I have tried converting to 8-bit image, adjusting the threshold then
analyzing the particles.  

When converted to greyscale the parts of the exposed soil and the plants

can occupy the same part of the thresehold.  Is there an established
method for doing this with Image J?

 

 

Malcolm Morrison

 

Agriculture Canada

 

Ottawa, Canada

 

 

[Tony Collins-2]

Try the K-means clustering plugin on your colour images.
http://ij-plugins.sourceforge.net/plugins/clustering/

It seems pretty good at separating similar colours. If you email me an
image, I can run it through an analysis.

Regards,

Tony

Morrison, Malcolm wrote:

>I am looking for a method to determine the green leaf area of a crop.  I
>
>have RGB .jpg photos of field plots at different stages and wish to
>
>develop a method to distinguish the leaf area from the soil area and
>
>then determine the % of the photo occupied by leaves.
>
>
>
>
>
>I have tried converting to 8-bit image, adjusting the threshold then
>analyzing the particles.  
>
>When converted to greyscale the parts of the exposed soil and the plants
>
>can occupy the same part of the thresehold.  Is there an established
>method for doing this with Image J?
>
>
>
>
>
>Malcolm Morrison
>
>
>
>Agriculture Canada
>
>
>
>Ottawa, Canada
>
>
>
>
>  
>

--
Tony Collins, Ph.D.
Facility Manager
Wright Cell Imaging Facility
Toronto Western Research Institute
13-407 McLaughlin Pavilion
399 Bathurst Street
Toronto, ON. M5T 2S8
tel. [phone] fax: [phone]
http://www.uhnresearch.ca/wcif

[Martin du Saire]

If you haven't already done so, consider exploring your thresholding
options using the 3D Color inspector or Color Thresholder
plugins.   Otherwise there are many filters that may work for you.
Take a look at the Plugins page

http://rsb.info.nih.gov/ij/plugins/index.html


M
At 09:31 AM 12/19/2005, you wrote:

>I am looking for a method to determine the green leaf area of a crop.  I
>
>have RGB .jpg photos of field plots at different stages and wish to
>
>develop a method to distinguish the leaf area from the soil area and
>
>then determine the % of the photo occupied by leaves.
>
>
>
>
>
>I have tried converting to 8-bit image, adjusting the threshold then
>analyzing the particles.
>
>When converted to greyscale the parts of the exposed soil and the plants
>
>can occupy the same part of the thresehold.  Is there an established
>method for doing this with Image J?
>
>
>
>
>
>Malcolm Morrison
>
>
>
>Agriculture Canada
>
>
>
>Ottawa, Canada
>
>
>
>